Cita APA (7a ed.)

Pennings, P., Keman, H., & Kleinnijenhuis, J. (2006). Doing research in political science (2nd ed.). Sage.

Cita Chicago Style (17a ed.)

Pennings, Paul, Hans Keman, y J. Kleinnijenhuis. Doing Research in Political Science. 2nd ed. London ; Thousand Oaks, Calif.: Sage, 2006.

Cita MLA (8a ed.)

Pennings, Paul, et al. Doing Research in Political Science. 2nd ed. Sage, 2006.